Specimen Requirements

Specimen Type: Serum

Container/Tube: Clot, plain, activator or gel separator

Specimen Volume: 1 mL

Specimen Minimum Volume: 0.3 mL

Collection Instructions:

1. A 10-12 hour fast is required.

2. The patient is given dexamethasone the evening before blood collection.

3. Contact pharmacy for dose and instructions.

4. Obtain a blood sample for cortisol assay the next morning.

5. Separation of serum from cells as soon as possible is recommended.

Additional Information:

1. Grossly hemolyzed, icteric, or lipemic samples are not acceptable.

2. Patients receiving Prednisolone or Prednisone (which is converted to Prednisolone in vivo) therapy may be falsely elevated. Caution must be exercised with cortisol determinations for patients undergoing therapy with these and structurally related synthetic corticosteroids. Heterophilic antibodies can react with reagent immunoglobulins, interfering with in vitro immunoassays.